What Does Corrosion Failure Mean?
Corrosion failure is a material failure related to corrosion. This condition requires immediate preservation and protection. Corrosion failure may require sampling and testing of corrosion products, such as in the case of microbiologically influenced corrosion (MIC), where viable cultures can provide the most meaningful results.
Studies of failure analysis are particularly useful in the chemical processing, refining, oil & gas and pulp & paper industries.
Corrosionpedia Explains Corrosion Failure
Corrosion failures often relate to material selection and the environment. Details of the material specifications, quality-assurance records, installation and maintenance records, and a history of the environment are all useful resources in resolving corrosion failures.
In the National Association of Engineers (NACE) guidelines, failures are classified into the eight forms of corrosion. The eight forms of corrosion are subdivided into three categories to reflect the ease of visual identification:
- Readily identifiable by ordinary visual examination - Pitting, galvanic, crevice corrosion
- May require supplementary means of examination - Erosion, fretting, intergranular, cavitation
- Verification usually required by microscopy (optical, electron microscopy, etc.) - Exfoliation, de-alloying, corrosion fatigue, stress corrosion cracking
Prediction of corrosion failure requires analysis which involves metallurgical investigations of components, equipment, metals, alloys, coatings, linings and structures due to corrosion, environmental degradation and abuse, misapplication of the particular metal and mechanical failure.
Recognizing the symptoms and mechanism of a corrosion failure is an important preliminary step to finding a solution. There are five methods of minimizing corrosion failures:
- Change to a more suitable material
- Modifications to the environment
- Use of protective coatings
- Application of cathodic or anodic protection
- Design modifications to the system or component
Most corrosion failures are not unique in nature. For any given failure, it is likely that a similar problem has been encountered and solved previously. Obtaining a history of the operation of the failed component is crucial to determining the cause of failure.